A sawing apparatus for a massive steel casting or beam typically has a saw blade rotatable about a horizontal axis and displaceable transversely of the axis and a conveyor that displaces an elongated workpiece longitudinally in a transport direction generally parallel to the saw-blade axis past the saw blade. The conveyor has a drive roller and holder rollers grip the workpiece upstream of the blade and feed it controlledly to and past the blade and may have a second such pair of rollers downstream of the blade to pull off the piece cut from the workpiece. Similarly an abutment block and a pusher block can be brought longitudinally together upstream of the blade to grip the workpiece and hold it in place during cutting.
In order to determine how much is being cut off the workpiece, one or more measuring rollers engage the workpiece immediately adjacent the drive and holder rollers upstream of the saw blade. One of these measuring rollers is provided with a rotation sensor that generates an output corresponding to the length of the workpiece that has moved past in contact with the measuring roller. This allows the machine to operate fairly automatically to cut measured pieces off the workpiece.
The disadvantage of this system is that long pieces must be discarded which have lengths that at least correspond to the distance between the upstream drive roll and the saw blade. In addition the assembly comprising the drive roller and holder roller is normally attached upstream of the blade on the frame carrying the blade, so that it is quite some distance from this blade. This increases the amount of waste and also the overall bulkiness of the apparatus. The size of the apparatus is increased yet further when it is used for angled cuts, not simply right-angle ones.